Water-dispersible agrochemical compositions

ABSTRACT

The invention relates to novel compositions of biologically active agents containing less than 50% by weight of a low use rate agrochemical active and a dispersing agent, which exhibit enhanced bio-availability on dilution and application in water.

This application is a continuation of U.S. patent application Ser. No.10/069,911 filed on Feb. 26, 2002, claiming priority from PCTApplication No. PCT/GB00/03307 filed on Aug. 25, 2000 and United KingdomApplication Serial No. 9920281.4, filed Aug. 26, 1999.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to novel chemical compositions in particular,compositions of biologically active agents and their use. The inventionis more particularly concerned with granular compositions of lowdose-rate agrochemicals, for example pesticides, suitably prepared by anextrusion process, which deliver the active ingredient of thecomposition efficiently to the substrate, for example a crop, which isto be treated.

The advantages of dispersible granule formulations of pesticides areknown and include their ease of handling and reduced worker exposurecompared to powder or liquid formulations. G. A. BELL, “Chemistry andTechnology of Agrochemical Formulations”, edited by D. A. Knowles(Kluver, 1998), pages 80-114, describes a range of dispersible granuletypes and processes for their manufacture.

Dispersible granules may be prepared by extrusion. U.S. Pat. No.3,954,439 discloses granular compositions of a herbicidal agent and oneor more surfactants and processes for the production of suchcompositions. The process described in U.S. Pat. No. 3,954,439 isapplicable to those herbicides which are substantially insoluble inwater. This patent states that it is obviously desirable that thegranules should have the highest possible content of active herbicidalmaterial. This patent further states that the process is preferablycarried out so as to give granules containing at least 50% of activeherbicide material and that it is more preferable that the granulesshould contain more than this, that is at least 80% and even up to 95%.The patent also teaches that it is obviously important to keep thesurfactant content down to a minimum, the total amount of surfactantpreferably being from 5 to 15%.

U.S. Pat. No. 5,872,078 relates to dry, water soluble and/or waterdispersible, agriculturally acceptable herbicidal compositionscontaining N-phosphonomethylglycerine or acceptable water-soluble saltthereof. The composition may comprise further optional ingredients, oneof which may be a co-herbicide. A large number of co-herbicides arelisted including sulfonylureas such as those available under the tradenames Ally, Classic, Oust, Glean and mixtures thereof. A liquidsurfactant is added to this mixture and extrusion granulation may beused to process the compositions described to form granules.

Improved delivery and bioavailability of the active ingredient inagrochemical compositions, especially of water insoluble actives forexample sulphonyl ureas, to achieve a desired agrochemical effect isdesirable. It is also desirable to achieve this effect in as costeffective manner as possible and conventionally this has been achievedby including as high a level of active ingredient as possible in aformulated composition.

We have now surprisingly found that a composition containing a lowerlevel of a primary active ingredient than conventionally employed incompositions containing the same ingredient, together with a suitabledispersing agent may conferenhanced delivery of the primary activeingredient to the crop to be treated. The invention is particularlyapplicable to a low use rate agrochemical for instance a pesticide, andespecially a water-insoluble agrochemical. Furthermore, as this enhancedeffect may be achieved at a lower level of active ingredient in thecomposition, the composition may include additional materials in theremaining “formulation space” to provide additional effects.

Accordingly, a first aspect of the invention provides an agrochemicalcomposition comprising a primary agrochemical active ingredient,preferably a low use rate active ingredient, at a level of less than 50%by weight of the composition and a dispersing agent, preferably anonionic and/or anionic surfactant(s).

The compositions according to the first aspect of the invention providesurprisingly beneficial bioavailability of the active for instance bymaking a larger proportion of the active biologically available in aliquid carrier, for example water, with which the composition is mixedin use than a known composition having a high level of active. Thecompositions disperse rapidly in the liquid carrier to form stablesuspensions of the active material(s) and subsequently dissolve at arate and to an extent higher than that achieved by conventionalcompositions containing the same ingredients.

This property provides enhanced efficacy of the agrochemicals withattendant reduced crop damage.

This enhanced bioavailability means that a given agrochemical effect maybe obtained using a lower total amount of agrochemical active thusproviding environmental benefits through lower use of agrochemicals.

Further, as the concentration of the active is lower than conventionallyemployed, there is a reduced risk that some of the active will not bedispersed or dissolve in the liquid carrier. Hence the risk of poordispersion or dissolution of the active in a liquid carrier leading tohigh localized concentrations of the active penetrating to the cropespecially the roots of plants and possibly damaging the crop isreduced.

A further advantage is that the lower level of primary active ingredientprovides enhanced flexibility in formulating a composition as comparedto conventional compositions employing high levels of active. Thus, theformulator may include a secondary active ingredient or other materialsas desired in the composition to provide an optimum effect or balance ofproperties.

It has also been surprisingly found that when low use-rate pesticides,such as water-insoluble compounds including sulfonyl ureas, for exampleas described in U.S. Pat. No. 5,872,078, are employed as the primaryactive ingredient with a secondary high rate use pesticide and asuitable dispersing agent at the required level, the rate and extent ofsolubility and thus the bioavailability, of the primary active or boththe actives may be increased as compared to granules containing theequivalent amount of each material alone. Optimally, the primary andsecondary actives are intimately mixed in suitable proportions.Suitably, optional conventional other ingredients such as one or moreadditional surfactants are included in the formulation and theingredients are processed into a suitable form, for examplewater-dispersible granules.

Accordingly the invention also provides in a preferred embodiment anagrochemical composition comprising as a primary active ingredient, alow use rate agrochemical active ingredient, at a level of less than 50%by weight of the composition and a secondary active ingredient,preferably a high use rate active ingredient, and a dispersing agent,preferably an anionic and/or nonionic surfactant.

In addition to the advantages referred to above for compositionaccording to the invention, the compositions provide at least anenhanced effect as regards the primary active and suitably an effectgreater than the combined additive affect of both the primary andsecondary active is observed where the composition contains a primaryand secondary active.

The term “low use rate” active denotes those agrochemical actives whichtypically are applied at a rate of less than 100 g/hectare and the term“high use rate” active denotes those agrochemical actives whichtypically are applied at a rate of more than 100 g/hectare.

The compositions of the present invention result in the individualcomponents being used at lower rates and with less phytotoxicity thanconventional compositions of the said active materials, against a widerange of pests and diseases.

The level of primary active ingredient is suitably selected according tothe particular compound to be used but is preferably less than 30% byweight of the composition, especially in the case of a low use rateactive. For example, chlorsulfuron may suitably be employed at a levelof less than 30%, for example 25% by weight of the composition. In apreferred embodiment, the primary active ingredient, for examplebensulfuron, is present at a level of less than 10% and more preferablyless than 2% by weight of the composition. In an especially preferredembodiment the primary active is present at a level of less than 1%.Suitably, the composition will contain the primary active at a level atwhich, on mixing with a liquid carrier, it provides a concentration ofactive which will provide a beneficial effect in treating crops. Thislevel may suitably be at 0.05% but is preferably at least 0.1% anddesirably at least 0.2% by weight of the composition although theprecise level may be adjusted according to the particular applicationand the particular primary active present in the composition.

Where a second active is employed, it is suitably present at a levelgreater than the level of the primary active ingredient. In a preferredembodiment the secondary active is present at a level of at least 30%,more preferably at least 50%, optimally at least 65%, for example 75% byweight of the composition.

The invention comprises a dry, free-flowing, dustless and rapidlydispersing granular formulation containing a low use rate pesticide ormixture of pesticides together with an additional high use ratepesticide. The terms composition and formulation are used herein to havethe same meaning.

A suitable dispersing agent(s) is/are incorporated into the formulationat a specific ratio so as to enable the rapid dispersion and subsequentdissolution of the low use rate and high use rate active material upondilution and subsequent application. Suitably, the weight ratio ofdispersing agent to the low use rate primary active ingredient in thecomposition is 0.1 to 10:1, preferably 0.4 to 6:1, for example about 4:1and about 5:1.

The invention is particularly suitable for, but not limited to, such lowuse-rate pesticides as: Abamectin, imidazolinone, azoxystrobin,bensulfuron-methyl, carfentrazone-ethyl, chlorsulfuron, cinosulfuron,clodinafop, clopyralid, lambda-cyhalothrin, deltamethrin, diflufenican,emamectin benzoate, fibronil, flurtamone, imazamethabenz-methyl,imazapyr, imazethapyr, imadacloprid, metsulfuron-methyl, milbectin,nicosulfuron, pirimisulfuron-methyl, rimsulfuron, sulfometuron,-methyl,thifensulfuron-methyl, tribenuron-methyl, and tirflusulfuron-methyl.Preferably the low use rate pesticide is a sulfonyl urea.

Suitable high use rate pesticides include: Abamectin, atrazine,benomylbentazone, bifenox, bromoxynil, captan, carbendazim, chloridazon,chlorothalonil, chlortoluron, lambda-cyhalothrin, cyhexatin, cymoxynil,alpha-cypermethrin, deltamethrin, dimethomorph, diuron, ethofumesate,fibronil, flurtamone, glyphosate, imazamethabenz-methyl, imazapyr,imazethapyr, imadacloprid, isoproturon, linuron, mancozeb, maneb,metamitron, methiocarb, metribuzin, milbectin, oxadixyl, oxyfluorfen,phenmedipham, propanil, propyzamide, simazine, thifensulfuron-methyl andthiram.

In an especially preferred embodiment, the low use rate pesticidecomprises bensulfuron-methyl and the high use rate pesticide comprisespropanil.

In a preferred embodiment, the dispersing agent comprises a surfactantwith nonionic surfactants and especially anionic surfactants beingpreferred. Examples of suitable dispersing agents include alkali metal,preferably sodium salts of lignosulphonates, naphthalene sulphonateformaldehyde condensates, tristyrylphenol ethoxylate phosphate esters,aliphatic alcohol ethoxylates, alkylphenol ethoxylates, ethyleneoxide/propylene oxide (EO-PO) block copolymers, “comb” graft copolymersand polyvinyl alcohol-vinyl acetate copolymers. Other dispersing agentsknown in the art may be employed as desired.

In addition to the dispersing agent, other components may be present inthe composition for example a wetting agent. Suitable wetting agentsinclude: alkali metal salts of alkylaryl sulphonates, alkyl arylsulphosuccinates and alkyl sulphates, preferably as the sodium salt.Other wetting agents, and other excipients known to those skilled in theart may be employed as desired including disintegrants for example:bentonite, modified starch and polyvinyl pyrrolidone; stabilisers, forexample citric acid, polyethylene glycol and butylated hydroxy toluene;and fillers, for example, starch, lactose, china clay, sucrose andkaolin; and flow-aids.

The granular compositions are preferably prepared by the methoddescribed in PCT application PCT/GB00/00163 the contents of which arehereby incorporated by reference. Suitably the process comprises,preparing a mix in the form of a free-flowing powder, preferably ahomogeneous powder, comprising the primary active ingredient and adispersing agent and optionally other components, preferably withoutforming a paste, and extruding the pre-mix in an extruder, for example alow pressure extruder to form the granules. A pre-mix optionallycontaining the secondary active ingredient may be mixed with thedispersing agent and the primary active ingredient to form the mix forextrusion. The dispersing agent may be liquid in which case anadditional liquid component is not required although a further liquidcomponent may be included as desired.

Suitable apparatus for the blending step(s) include a low-shear, highintensity blender such as a Lodige Ploughshare mixer, ribbon, Y-cone,double cone or trough blender, so that a free-flowing powder is formed.The mix is fed directly or indirectly into a suitable low-pressureextruder, such as that described in WO 96/26828, so that the premix iscompacted against the apertures in the screen and forced through.

In a preferred embodiment, the composition of the mix and the extrudersettings are such that the formation of a paste before extrusion isavoided and the material being processed remains a free flowingparticulate material during the formation of the pre-mix. In particular,the material optimally does not form a paste prior to extrusion.However, as the composition may contain one or more liquid components,it may be wet or dry provided that it remains free-flowing andparticulate during the process. In this context, a paste may beconsidered as a mass of material, for example an agglomerate, whichcontains sufficient liquid or is at such a temperature that theparticulate material being processed forms into an agglomerate which ismouldable or deformable and which is not free-flowing. Thus, a pastedoes not disintegrate into finer particles on application of shear, forexample by rubbing between fingers, but rather remains as anagglomerated mass and the shear acts to mould or deform the agglomerate.

If desired, the components of the composition, either in sequence, alltogether or some in sequence and others together are first mixed, forexample in a blender so that a uniform blend is obtained which is thenpassed through a suitable milling system such as an air mill, pin millor air-swept impact mill so that a fine powder (the pre-mix) comprisingan average particle size of 0.5 to 20 microns, or more preferablybetween 0.5 to 5 microns is obtained. The powder thus obtained issuitably agglomerated, so that uniform, dust-free granules are obtained,preferably by the process described in PCT/GB00/00163. This preferredmethod involves the extrusion of the wetted powder which is then in theform of a freely flowing homogeneous powder, in a low temperature, lowpressure extruder, for example as described in EP-A-812256.

Where present, the low use rate and high use rate agrochemicals may becombined in the formation of the dry pre-mix with the other formulationingredients for example dispersing agents or alternatively the pre-mixmay be prepared with one of the agrochemicals and the other added to themilled pre-mix. This alternative approach is preferred when the high userate pesticide is propanil which is suitably incorporated in the drypre-mix, and the low use rate pesticide is then added to the pre-mix andblended with it prior to granulation.

In a second aspect, the invention provides a method of treating a plantby applying a herbicidally effective amount of a composition accordingto the present invention to the plant or to the locus of the plant.

The present invention enables the composition of the invention to beused at a lower rate of use (mass of composition/unit area, typicallygrammes per hectare) to achieve a given effect than known compositions.Suitably the agrochemical active is applied to the plant or locus of theplant at a rate of use of less than 75%, more preferably less than 50%of the conventional rate of use for the active in commercially availablecompositions.

In a preferred embodiment, a composition comprising a sulphonyl urea lowuse rate active for example bensulfuron, is applied in use at a rate ofuse of less than 50 g/hectare, especially less than 30 g/hectare andoptimally less than 20 g/hectare. Typically, a commercially availablecomposition containing in excess of 50% by weight of the composition ofbensulfuron-methyl may be employed at a rate of use of 60 g/hectare ormore. In another preferred embodiment, the composition comprises a highuse rate secondary active comprising propanil in addition to a sulphonylurea active, for example bensulfuron, and suitably the secondary activeis applied in use at a rate of less than 7000 g/hectare, preferably lessthan 5000 g/hectare and especially at a rate of less than 3200g/hectare.

Where the plant is a weed, suitably, the treatment is such as to controlor kill the weed. Generally, the composition is applied to the plant orits locus by means of a liquid carrier, typically water, with which thecomposition is mixed prior to application. If desired, the compositionmay be mixed with a liquid carrier to form a concentrate suitable forsubsequent mixing with a liquid carrier. The application of thecomposition to the plant or its locus in solid or concentrate formespecially where water is present in the vicinity of the plant throughnatural precipitation is also within the ambit of the invention.

In water, suitably the composition is diluted for use to a level of 10to 500 mg/l and preferably 20 to 300 mg/l. The dilution is suitablyselected according to the composition used, the type of application, thestate of growth of the plants to be treated and other factors known tothose skilled in the art.

In a third aspect, the invention provides for use of a compositionaccording to the invention as an agrochemical, for example a low userate herbicide.

This invention relates to novel compositions and to methods of treatingplants, for example killing or controlling weeds by applying a reducedamount of the active ingredient(s), suitably diluted in water, than thatnormally recommended for such active(s) against such weeds. In additionthe invention allows for the avoidance of subsequent applications of thesaid actives, thus further reducing the amount of pesticide used.

The following examples illustrate the invention in an non-limitingmanner.

EXAMPLE 1

Chlorsulfuron 25 WG Ingredient Trade name % w/w Chlorsulfuron technical(95%) (technical a.i.) 26.32 Sodium lignosulfonate Ultrazine NA 12.50Dodedyl benzene sulphonate, Arylan SX85 5.00 Sodium salt Lactose Lactose56.18Method

The chlorsulfuron technical was airmilled using a Gem-T airmill beforecombining with other components. The technical, Ultrazine and Arylancomponents were blended until uniform in a high speed blender. Thelactose was then added and the formulation blended for a further 15seconds. 12% distilled water was added whilst blending. The wettedpremix (free flowing powder) was fed to a basket extruder as describedin EP-A-812256 through a 1 mm screen. A compacted extrudate was obtainedand the resulting granules dried at 60 C for 8 minutes. The driedgranules were then sieved through 2 mm and 500 micron sieves.

Comparative Example A

Chlorsulfuron 75 WG Ingredient Trade name % w/w Chlorsulfuron technical(95%) 78.95 technical a.i.) Sodium lignosulfonate Ultrazine NA 12.50 Diisopropyl naphthalene sulfonate, Galoryl MT704 1.00 sodium salt LactoseLactose 7.55Method

The chlorsulfuron technical was airmilled using a Gem-T airmill beforecombining with other components. The milled chlorsulfuron technical,Ultrazine and Galoryl components were blended until uniform in a highspeed blender. The lactose was then added and the formulation blendedfor a further 15 seconds. 17% distilled water was added whilst blending.The wetted premix (free flowing powder) was fed to a basket extruder asdescribed in EP-A-812256 through a 1 mm screen. A compacted extrudatewas obtained and the resulting granules dried at 60 C for 8 minutes. Thedried granules were then sieved through 2 mm and 500 micron sieves.

The solubility of the compositions produced according to Example 1 andComparative Example A and Glean (commercially available 75 WG product)and airmilled technical was tested using the method below:

Solubility Test Method

200 mls water was poured into a jacketed glass vessel and allowed toreach 25 C. A Grant recirculator was used to maintain the temperature at25 C+/−1 C. A magnetic stirrer at a set speed was used to stir thewater. The specified weight of granules was then added to the water andallowed to disperse for 30 seconds before a timer was started. A 2 mlssample was removed using a syringe after 5 minutes and filtered using a0.45 micron syringe filter. The solution was then analysed to determinethe active concentration using a HPLC method. The theoreticalconcentration assuming 100% solubility was calculated using an assayobtained using the HPLC.

The following data was obtained: % active added Type of to water thatDilution water used dissolved rate (mgs to dilute after 5 FormulationProduct a.i./L) granules minutes Example 1 25 WG 69 Distilled 98Comparative 75 WG 72 Distilled 95 Example A Glean (Du 75 WG 72 Distilled67 Pont) Airmilled — 91 Distilled <2 technicalConclusions

Both the 75 and 25 extruded WG formulations have a significantly highersolubility in distilled water compared to the commercial product. Thetechnical is not readily soluble in distilled water at this temperature.

EXAMPLE 2

Bensulfuron-methyl 1 WG Ingredient Trade name % w/w Bensulfuron methyltechnical (95%) (technical 1.05 a.i.) Naphthalene sulfonic acid GalorylDT505 12.70 Formaldehyde condensate, sodium salt Di isopripylnaphthalene sulfonate, Galoryl MT704 1.00 sodium salt Lactose Lactose85.25Method

The technical and Galoryl DT505 were blended together until uniform. Theblend was then airmilled using a Gem-T airmill. The milled premix,Galoryl MT704 and lactose were blended until uniform in a high speedblender. The lactose was then added and the formulation blended for afurther 15 seconds. 12% distilled water was added whilst blending. Thewetted premix (free flowing powder) was fed to a basket extruder asdescribed in EP-A-812256 through a 1 mm screen. A compacted extrudatewas obtained and the resulting granules dried at 60 C for 8 minutes. Thedried granules were then sieved through 2 mm and 500 micron sieves.

Comparative Example B

Bensulfuron-methyl 60 WG Ingredient Trade name % w/w Bensulfuron methyltechnical (95%) (technical 64.21 a.i.) Naphthalene sulfonic acid GalorylDT505 12.70 Formaldehyde condensate, sodium salt Di isopripylnaphthalene sulfonate, Galoryl MT704 1.00 sodium salt Lactose Lactose22.08

The composition of Comparative Example B was prepared using the methodset out in Example 2.

The solubility of the compositions of Example 2 and Comparative ExampleB were then tested using the method detailed in Example 1. The followingdata was obtained: Type of water % active added Dilution used to towater that rate (mgs dilute dissolved after Formulation Product a.i./L)granules 5 minutes Londax 60 WG 300 Tap 12 Comparative 60 WG 291 Tap 25Example B Londax 60 WG 75 Tap 19 Comparative 60 WG 73 Tap 46 Example BExample 2  1 WG 240 Tap 71

EXAMPLE 3 Propanil and Bensulfuron-Methyl Combined WG (75% Propanil and0.75% Bensulfuron)

Propanil Premix

A premix of Propanil was prepared as follows: Ingredient Trade name %w/w Propanil technical (97.0% a. i.) Technical 82.47 Starch Paselli 1.00Nonionic surfactant and sodium Stepsperse DF 5.00 Lignosulphonate blend500 Modified sodium lignosulphonate Ufoxane 3A 5.00 Hydrated aluminiumsilicate China Clay to 1.00

The ingredients were blended in a medium shear, high speed blender for 5minutes until uniform. The resulting mixture was passed through an airmill to obtain a fine powder. The powder was wetted with 19.5% water(based on the dry weight of powder) and blended until a damp freeflowing powder was formed. The premix was used in the following blendswith bensulfuron: Ingredient Trade name % w/w Bensulfuron methyltechnical (95%) (technical a.i.) 0.79 Propanil 80% milled premix 93.75Naphthalene sulfonic acid Galoryl DT505 0.31 Formaldehyde condensate,sodium salt China clay China clay GTY 5.15

The technical and Galoryl DT505 were blended together until uniform. Theblend was then airmilled using a Gem-T airmill. The milledbensulfuron-methyl and milled propanil premixes, Galoryl MT704 and chinaclay were blended until uniform in a high speed blender. 17% distilledwater was added whilst blending. The wetted premix (free flowing powder)was fed to a basket extruder as described in EP-A-812256 through a 1 mmscreen. A compacted extrudate was obtained and the resulting granulesdried at 60 C for 8 minutes. The dried granules were then sieved through2 mm and 500 micron sieves.

EXAMPLE 4 Propanil and Bensulfuron-Methyl Combined WG (75% Propanil and0.375% Bensulfuron)

Ingredient Trade name % w/w Bensulfuron-methyl technical (95%)(technical a.i.) 0.39 Propanil 80% milled premix — 93.75 Naphthalenesulfonic acid Galoryl DT505 0.16 Formaldehyde condensate, sodium saltChina clay China clay GTY 5.70

The technical and Galoryl DT505 were blended together until uniform. Theblend was then airmilled using a Gem-T airmill. The milledbensulfuron-methyl and milled propanil premixes, Galoryl MT704 and chinaclay were blended until uniform in a high speed blender. 17% distilledwater was added whilst blending. The wetted premix (free flowing powder)was fed to a basket extruder as described in EP-A-812256 through a 1 mmscreen. A compacted extrudate was obtained and the resulting granulesdried at 60 C for 8 minutes. The dried granules were then sieved through2 mm and 500 micron sieves.

The above combination formulations were tested using the solubilitymethod detailed in Example 1. The following data was obtained: Type of %active added % Dilution water used to water that bensulfuron- rate (mgsto dilute dissolved after Formulation methyl a.i. a.i./L) granules 5minutes Example 3 0.75 75 Tap 66 0.75 112.5 Tap 64 Example 4 0.375 37.5Tap 83 0.375 56 Tap 84

Further solubility testing up to 2 hours was carried out using the samemethod as for Example 1 except the granules were diluted in 1000 mlswater and samples were taken after 5, 30, 60, 90 and 120 minutes. Thefollowing results were obtained using 37.5 mgs a.i./litre (all in tapwater). Data for Comparative Example B (bensulfuron-methyl 60 WG) andLondax (commercial bensulfuron-methyl 60 WG) at the same dilution rateis shown for comparison. % active added to water that dissolved TimeComparative (mins) Example 5 Example B Londax 5 67 42 15 30 67 52 32 6067 57 39 90 66 57 49 120 69 62 53Conclusions

The solubility rate of bensulfuron-methyl in a granule which alsocontains an active that is used a high rate per hectare, issignificantly higher compared with diluting the bensulfuron-methyl as a60 WG.

EXAMPLE 5 Propanil and Bensulfuron-Methyl Combined WG (75% Propanil and0.24% Bensulfuron)

Ingredient Trade name % w/w Bensulfuron methyl technical (95%)(technical a.i.) 0.25 Propanil 80% milled premix — 93.72 Naphthalenesulfonic acid Galoryl DT505 0.10 Formaldehyde condensate, sodium saltChina clay China clay GTY 5.90

The processing method set out in Example 4 was employed, with thebensulfuron-methyl being milled as a premix with the Galoryl DT505. Thesolubility of the bensulfuron-methyl in the above formulation was thentested using the method set out in Example 4. The following results wereobtained using 25 mgs and 31.3 mgs bensulfuron-methyl a.i./litre (in tapwater). % bensulfuron-methyl active added to water that dissolvedExample 5 Example 5 Time (mins) (25 mgs/L) (31.3 mgs/L) 5 89 91 30 90 9260 94 92 90 93 96 120 97 95Field Evaluation

A composition according to Example 4 was evaluated in the field incomparison with commercial formulations containing the same activeingredients.

Treatment Details Treatment Number Composition Rate of use (g/Hectare)Product Control Untreated Control — 1 Stam 80 EDF 4,000 g at GrowthStage BBCH 12-13 8,000 g at Growth Stage BBCH 21-21 2 Stam 80 EDF +4,000 g at Growth Stage BBCH 12-13 Londax 60   100 g at Growth StageBBCH 12-13 3 Example 4 4,000 g at Growth Stage BBCH 12-13

The above treatments were applied in 400 1 water/ha on Rice v. lotoagainst Gramineae family weeds. The weeds were assessed at −1, +4, +16and +32 days after application by the efficacy assessment guidelinesprovided by EPPO Guidelines PP1/181(2), PP1/152(2) and 1/62(2).

Stam 80 EDF is a commercial formulation containing 80% propanil in theform of an extruded granule. Londax 60 is a commercial formulationcontaining 60% bensulfuron-methyl in the form of a fluid bed granule.

Results

Assessment: 1 day before 1^(st) Application Treatment 1 Treatment 2Treatment 3 Control % % % % % % Weeds % cov. cov. eff. Sympt. cov. eff.Sympt. cov. eff. Sympt. Heteranthera 38.0 37.0 0.0 n.a. 35.0 0.0 n.a.35.0 0.0 n.a. limosa Heteranthera 0.0 1.0 0.0 n.a. 0.0 0.0 n.a. 0.0 0.0n.a. reniformis Echinochloa crus- 1.0 1.0 0.0 n.a. 1.0 0.0 n.a. 1.0 0.0n.a. galli Panicum 1.0 1.0 0.0 n.a. 1.0 0.0 n.a. 1.0 0.0 n.a.dichotomiflorum Scirpus maritimus 1.0 1.0 0.0 n.a. 1.0 0.0 n.a. 2.0 0.0n.a. Scirpus mucronatus 1.0 1.0 0.0 n.a. 2.0 0.0 n.a. 1.0 0.0 n.a.

Assessment: 4 days after 1^(st) Application Treatment 1 Treatment 2Treatment 3 Control % % % % % % Weeds % cov. cov. eff. Sympt. cov. eff.Sympt. cov. eff. Sympt. Heteranthera 55.0 55.0 70.0 WC 34.0 80.0 W 40.050.0 W limosa Heteranthera 0.5 0.0 0.0 n.a. 0.6 0.0 n.a. 0.0 0.0 n.a.reniformis Echinochloa 7.0 0.0 0.0 n.a. 1.0 0.0 n.a. 1.0 0.0 n.a.crus-galli Panicum 5.5 0.0 0.0 n.a. 1.0 0.0 n.a. 1.0 0.0 n.a.dichotomiflorum Scirpus 1.0 4.0 90.0 W 0.0 0.0 n.a. 3.0 70.0 W maritimusScirpus 2.0 1.0 60.0 W 2.0 60.0 W 5.0 70.0 W mucronatus

Assessment: 16 days after 1^(st) Application Treatment 1 Treatment 2Treatment 3 Control % % % % % % Weeds % cov. cov. eff. Sympt. cov. eff.Sympt. cov. eff. Sympt. Heteranthera 55.0 1.0 99.0 W.C. 18.0 80.0 W.C.2.0 98.0 W limosa Heteranthera 0.0 0.0 0.0 n.a. 0.0 0.0 n.a. 0.0 0.0n.a. reniformis Echinochloa 10.0 0.0 0.0 n.a. 1.0 0.0 n.a. 0.0 0.0 n.a.crus-galli Panicum 15.0 0.0 0.0 n.a. 1.0 0.0 n.a. 0.0 0.0 n.a.dichotomiflorum Scirpus 5.0 0.0 0.0 n.a. 0.0 0.0 n.a. 1.0 98.0 Wmaritimus Scirpus 15.0 0.0 0.0 n.a. 0.0 0.0 n.a. 0.0 0.0 n.a. mucronatus

Assessment: 32 days after 1^(st) Application Treatment 1 Treatment 2Treatment 3 Control % % % % % % Weeds % cov. cov. eff. Sympt. cov. eff.Sympt. cov. eff. Sympt. Heteranthera limosa 37.0 0.0 0.0 n.a. 1.0 0.0n.a. 0.0 0.0 n.a. Heteranthera 1.0 0.0 0.0 n.a. 0.0 0.0 n.a. 0.0 0.0n.a. reniformis Echinochloa crus- 10.0 0.0 0.0 n.a. 0.0 0.0 n.a. 0.0 0.0n.a. galli Panicum 15.0 0.0 0.0 n.a. 2.0 0.0 n.a. 0.0 0.0 n.a.dichotomiflorum Scirpus maritimus 5.0 0.0 0.0 n.a. 0.0 0.0 n.a. 0.0 0.0n.a. Scirpus mucronatus 32.0 0.0 0.0 n.a. 0.0 0.0 n.a. 0.0 0.0 n.a.Abbreviations

-   % cov.: % area covered by weeds-   % eff.: % herbicide efficacy (% of weeds showing necrotic symptoms):-   Sympt.: symptoms (W: withered; C:chlorotic; n.a. not applicable)    Conclusions

The above results demonstrate the composition of Example 4 (15 g/habensulfuron-methyl combined with 3,000 g/ha propanil) providesequivalent control to the commercial products tested when applied atless than ⅓rd of the propanil in the Stam 80 EDF treatment (twoapplications, one 3200 a.i. g/ha and one 6400 a.i. g/ha propanil) and ¼of the Londax rate (one application of 60 g/ha bensulfuron-methyl tankmixed with one application of 3,200 g/ha propanil).

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 33. A waterdispersible agrochemical composition comprising a primary agrochemicalactive ingredient at a level of less than 50% by weight of thecomposition and a dispersing agent the composition being obtainable by aprocess comprising preparing a wetted mix in the form of a free-flowingpowder comprising the primary active ingredient and the dispersing agentand optionally other components wherein at least one of the dispersingagent and optional other component is liquid and extruding the mix toform granules.
 34. A composition according to claim 33 in which theprimary active ingredient is selected from bensulfuron-methyl,chlorsulfuron, cinosulfuron, metsulfuron-methyl, nicosulfuron,primisulfuron-methyl, rimsulfuron, sulfometuron-methyl,thifensulfuron-methyl, and triflusulfuron-methyl.
 35. A compositionaccording to claim 33 further comprising a high use rate secondaryactive ingredient.
 36. A composition according to claim 35 in which thehigh use rate secondary active ingredient is selected from abamectin,atrazine, benomyl, bentazone, bifenox, bromoxynil, captan, carbendazim,chloridazon, chlorothalonil, chlortoluron, lambda-cyhalothrin,cyhexatin, cymoxanil, alpha-cypermethrin, deltamethrin, dimethomorph,diuron, ethofumesate, fipronil, flurtamone, glyphosate,imazamethabenz-methyl, imazapyr, imazethapyr, imidacloprid, isoproturon,linuron, mancozeb, maneb, metamitron, methiocarb, metribuzin,milbemectin, oxadixyl, oxyfluorfen, phenmedipham, propanil, propyzamide,simazine, thifensulfuron-methyl and thiram.